UNIVERSITY PARK, Pa. -- Childhood obesity rates are on the rise in the U.S., with Mexican-origin children having the highest obesity rates across all ethnic groups. Penn State researchers are looking into possible factors that influence the diets of these children.

Molly Martin, associate professor of sociology and demography at Penn State, is interested in social stratification, or divisions, in this ethnic group. “The risks of obesity are stratified among Mexican-origin children according to their generation status – the number of generations their family has been in the U.S.,” Martin explained.

Prior research has found that Mexican-origin immigrant and U.S.-born children with immigrant parents (first and second generation) are more likely to be overweight than their peers in Mexico and third generation Mexican-origin children – those of U.S.-born parents – but Martin wanted to find out why.

Martin and her research team, including Jennifer Van Hook, professor of sociology and demography and director of Penn State’s Population Research Institute; and Susana Quiros, graduate student in sociology and demography at Penn State, focused on the family’s socioeconomic status (SES) to see if it changed the dietary risks linked to generation status. According to Martin, this is the first study to explore the intersection between SES and generation status for children’s nutrition.

“Historically, Mexican-origin immigrant families have been at the bottom of the socioeconomic distribution,” said Martin. “We focused on children's nutrition because we know from previous research poor nutrition is a risk factor for childhood obesity and because immigrant families' diets frequently decline with increasing exposure to the U.S.”

Martin used data from the continuous National Health and Nutrition Examination study from 1999 to 2009 to test associations between generational status, nutrition of Mexican-origin children between ages 5 and 17, and the family’s socioeconomic status.

The research team theorized children who were born in Mexico had more early life exposures to traditional Mexican foods, which helped them develop preferences for those foods. Meanwhile, they discovered U.S-born children with immigrant parents found the stereotypical American foods like burgers, fries, and soda more appealing. “Children of immigrants often want to fit in with their U.S. peers, and part of fitting in is eating the same foods,” Martin said.

The research team also found that high status Mexican-origin parents – those with higher education and incomes – were able to buffer their children against many of these dietary declines. “Immigrant families that successfully integrate into American society have better outcomes, while those families that struggle economically face additional risks, including their children’s health,” explained Martin.

The largest dietary deficits were found among third-generation Mexican-origin youth in families with the lowest SES status. “The results weren’t entirely expected, as we've seen in other studies a higher socioeconomic status can lead to declines in health due to access of more calorie-dense foods, electronics, and a more sedentary lifestyle.”

In the future, Martin said her team would like to more closely examine other factors impacting childhood obesity rates in this ethnic group, including where these children consume most of their meals − at home, school, or other environments − and how their diets vary by generation and education levels.